My take is that this is a huge UI improvement for AI speech to text, which a lot of Deaf people are already using to listen to conversations. It seems particularity great because it allows this technology to provide situational awareness while, for example, walking.
It's important to remember, though that, for conversations where you're trying to include a Deaf person who isn't good at speaking or chooses not to speak, speech to text is a fundamentally unequal communication modality. They will be able to "receive" but they won't be able to "transmit", which makes for extremely lopsided conversations. There is no substitute for taking the time to learn a sign language or to have conversations via writing (no substitute for sign language as it requires a lot of patience from both parties).